Systems, methods, and devices for providing illumination in an endoscopic imaging environment

ABSTRACT

The disclosure relates to an endoscopic light source that includes a first emitter. The first emitter may emit light of a first wavelength at a dichroic mirror which reflects the light of the first wavelength to a plurality of optical fibers. The endoscopic light source further comprises a second emitter. The second emitter may emit light of a second wavelength at a second dichroic mirror which reflects the light of the second wavelength to the plurality of optical fibers. In one embodiment, the first dichroic mirror may be transparent to the light of the second wavelength, allowing the light of the second wavelength to pass through the first dichroic mirror.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/855,919, filed Dec. 27, 2017, and claims the benefit of U.S.Provisional Application No. 62/439,330, filed Dec. 27, 2016, and U.S.Provisional Application No. 62/522,239, filed Jun. 20, 2017, which areincorporated herein by reference in their entirety, including but notlimited to those portions that specifically appear hereinafter, theincorporation by reference being made with the following exception: Inthe event that any portion of the above-referenced applications areinconsistent with this application, this application supersedes saidabove-referenced applications.

TECHNICAL FIELD

The present disclosure relates generally to endoscopic imaging and moreparticularly relates to systems, methods and devices for providingillumination in an endoscopic imaging environment.

BACKGROUND

In endoscopic systems, artificial light must be provided for operationof an image sensor within an endoscope. While conventional systems haveused various lighting solutions, including incandescent bulbs, lightemitting diodes, and lasers, to provide light for an image sensor of anendoscope, when disposed within a body of a person (or animal),characteristics of light provided by these solutions result inendoscopic images with low resolution and quality.

One characteristic of this provided light is the intensity of theprovided light versus power transmitted into a waveguide. It isdesirable to provide a maximum amount of light at the lowest possiblepower rating with the purpose of not burning out a light waveguidewithin an endoscope. At the same time, however, it is undesirable, inthe case of lasers, to provide too much directed light at a scenebecause this directed light results in glare and a non-homogenousmixture of light at the scene. This non-optimal scene lighting may makeoperation of the endoscope more difficult for the user.

Another characteristic of this provided light is the angle at which thelight is provided. For example, variations in the angle of lighttransmitted into a waveguide leads to variations in the amount of lightthat is emitted from the waveguide. This variation in angle can alsolead to a non-homogenous mixture of light at a scene. This non-optimalscene lighting may make operation of the endoscope more difficult forthe user.

Accordingly, it is one object of this disclosure to provide a lightemitter which provides a homogenous lighting environment of the correctintensity and angle to efficiently light an endoscope scene for an imagesensor.

SUMMARY

Disclosed herein is an endoscopic light source that includes a firstemitter and a second emitter. The first emitter may emit light of afirst wavelength at a dichroic mirror which reflects the light of thefirst wavelength to a plurality of optical fibers. The second emittermay emit light of a second wavelength at a second dichroic mirror whichreflects the light of the second wavelength to the plurality of opticalfibers. The first dichroic mirror may be transparent to the light of thesecond wavelength, allowing the light of the second wavelength to passthrough the first dichroic mirror.

The endoscopic light source, may further include a third emitter. Thethird emitter may emit light of a third wavelength at a dichroic mirrorwhich may reflect the light of the third wavelength to the plurality ofoptical fibers. Both the first dichroic mirror and the second dichroicmirror may be transparent to the light of the third wavelength, allowingthe light of the third wavelength to pass through the first and seconddichroic mirrors.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a system for providingillumination to a light deficient environment, according to oneembodiment.

FIG. 2 is a graphical view of the delay and/or jitter between a controlsignal and emitted light, according to one embodiment.

FIG. 3 illustrates a cross section of a fiber bundle having seven fiberswith uneven light distribution, according to one embodiment.

FIG. 4 is a graphical view of a top hat profile and a Gaussian profile,according to one embodiment.

FIG. 5 is a schematic block diagram illustrating a light source having aplurality of emitters, according to one embodiment.

FIG. 6 is a schematic block diagram illustrating a light source having aplurality of emitters, according to another embodiment.

FIG. 7 is a schematic block diagram illustrating a light source having aplurality of emitters, according to yet another embodiment.

FIG. 8 is a schematic side view illustrating light output from anoptical fiber, according to one embodiment.

FIG. 9 is a schematic diagram illustrating aiming of fibers of a fiberbundle at an output end, according to one embodiment.

FIG. 10 is a schematic diagram illustrating output of light using glassfibers, according to one embodiment.

FIG. 11 is a schematic diagram illustrating output of light using adiffuser at an output, according to one embodiment.

FIG. 12 is a schematic flow chart diagram illustrating a method forproviding light to an imaging scene in a light deficient environment,according to one embodiment.

FIG. 13 is a schematic flow chart diagram illustrating a method forproviding light to an imaging scene in a light deficient environment,according to another embodiment.

FIG. 14 is a schematic flow chart diagram illustrating a method forproviding light to an imaging scene in a light deficient environment,according to another embodiment.

FIG. 15 is a schematic flow chart diagram illustrating a method forproviding light to an imaging scene in a light deficient environment,according to yet another embodiment.

FIG. 16 is a schematic diagram illustrating a single optical fiberoutputting via a diffuser at an output according to one embodiment.

FIG. 17 is a schematic diagram illustrating a system for providingillumination to a light deficient environment according to oneembodiment.

DETAILED DESCRIPTION

Imaging in a light deficient environment with optical image sensors(such as visible light CMOS or CCD or other imaging arrays) generallyrequires artificial illumination. With regard to endoscopic imaging, anendoscope often includes a tubular member, which may be inserted into apatient's body. A tip of the lumen may include an imaging sensor orother optical component for gathering light and capturing an image of ascene within the patient's body. Endoscopes must be sterile, due totheir use in a body or during a medical procedure. Endoscopes orendoscopic components with sufficiently low price may be used asdisposable or reposable components, which may reduce the costs andeffort required by hospitals or medical personnel in sterilizing ormanaging the sterilization or state or reusable components.

The present disclosure presents systems, methods, and devices providingillumination in an endoscopic imaging environment that reduce expenseand/or improve image quality for imaging in a light deficientenvironment. The methods, systems, and devices disclosed herein may beused in combination with or as alternatives to any of the teaching,technology, or functionality discussed and presented in one or more of:(1) U.S. Patent Application Publication No. US 2014/0163319 A1; (2) U.S.Pat. No. 9,509,917; and (3) U.S. Pat. No. 9,516,239, all of which areincorporated herein by this reference in their entireties.

A detailed description of systems and methods consistent withembodiments of the present disclosure is provided below. While severalembodiments are described, it should be understood that this disclosureis not limited to any one embodiment, but instead encompasses numerousalternatives, modifications, and equivalents. In addition, whilenumerous specific details are set forth in the following description inorder to provide a thorough understanding of the embodiments disclosedherein, some embodiments may be practiced without some or all of thesedetails. Moreover, for the purpose of clarity, certain technicalmaterial that is known in the related art has not been described indetail in order to avoid unnecessarily obscuring the disclosure.

Turning to the figures, FIG. 1 is a schematic diagram illustrating asystem 100 for providing illumination to a light deficient environment,such as for endoscopic imaging. The system 100 includes a light source102, a controller 104, a jumper waveguide 106, a coupler 108, a lumenwaveguide 110, a lumen 112, and an image sensor 114 with accompanyingoptical components. The light source 102 generates light that travelsthrough the jumper waveguide 106 and the lumen waveguide 110 toilluminate a scene at a distal end of the lumen 112. The lumen 112 maybe inserted into a patient's body for imaging, such as during aprocedure or examination. The light is output as illustrated by dashedlines 116. A scene illuminated by the light may be captured using theimage sensor 114 and displayed for a doctor or other medical personnel.The controller 104 may provide control signals to the light source 102to control when illumination is provided to a scene. If the image sensor114 includes a CMOS sensor, light may be periodically provided to thescene in a series of illumination pulses between readout periods of theimage sensor 114 during what is known as a blanking period. Thus, thelight may be pulsed in a controlled manner to avoid overlapping intoreadout periods of the image pixels in a pixel array of the image sensor114.

In one embodiment, the lumen waveguide 110 includes a plurality ofoptical fibers. The optical fibers may be made of a low cost material,such as plastic to allow for disposal of the lumen waveguide 110 and/orother portions of an endoscope. The jumper waveguide 106 may bepermanently attached to the light source 102. For example, a jumperwaveguide 106 may receive light from an emitter within the light source102 and provide that light to the lumen waveguide 110 at the location ofthe coupler 108. In one embodiment, the jumper waveguide 106 may includeone or more glass fibers. The jumper waveguide may include any othertype of waveguide for guiding light to the lumen waveguide 110. Thecoupler 108 may couple the jumper waveguide 106 to the lumen waveguide110 and allow light within the jumper waveguide 106 to pass to the lumenwaveguide 110. In one embodiment, the lumen waveguide 110 may bedirectly coupled to a light source without any intervening jumperwaveguide 106.

FIG. 2 illustrates a graphical view of the delay and/or jitter between acontrol signal 202 and emitted light 204. The control signal 202 mayrepresent a signal provided to a controller or drive circuit, such asthe controller 104 or a driver within the light source 102 of FIG. 1. Asillustrated, there is a delay of t1 between the control signal 202 goinghigh (e.g., turning on) and light being emitted 204. There is a delay oft2 between the control signal 202 going low (e.g., turning off) andlight being emitted 204. For example, the delays t1 and t2 may includesome constant delay as well as some non constant variation resultingfrom the amount of jitter in a controller and/or driver. The amount ofjitter or variation in a system or device is described by the jitterspecification (jitter spec). For example, if t1 has a value of 1microsecond then t2 may have a value of 1 microsecond plus or minus thejitter spec of the controller or driver.

Because jitter is not under control of the system or user, the jitterspec represents the amount of unpredictable time variation that may bepresent. If the jitter spec is too large with respect to a pulse oflight, significant reductions in image quality or image brightnessvariations can result. For example, in a video endoscopic system,different lines or frames within the video or series of images can havea different brightness, leading to flicker and overall reduced video orimage quality. For example, if a controller has a jitter spec of 10% ofa pulse of light, the pulse of light may vary from 90% of its desiredlength to 110% of its desired length. This may lead to brightnessvariations between images or lines of an image within a video of up to⅓. Furthermore, a large jitter spec may result in light being emittedduring readout. If light is emitted during readout, significantvariations between pixels and lines may reduce image quality. See, forexample, FIG. 2D and associated discussion in U.S. Patent ApplicationPublication No. US 2014/0163319 A1. Thus, if a jitter spec is largeenough, a pulse may be limited in size to avoid overlapping into areadout time period of the image sensor 114. Limits on the pulse sizemay require a reduction in frame rate (increase in time between capturedimages or larger blanking periods) or may result in reductions inbrightness, which may reduce the ability of an image sensor 114 tocapture detailed images.

In one embodiment, the controller 104 as in FIG. 1 has a jitter specsmall enough to reduce variations in brightness or image quality. In oneembodiment, the driver must have a tolerance or jitter spec of about 1micro second or less. In one embodiment, the tolerance or jitter spec ofthe driver is about 50 nanoseconds. The reduced jitter spec may beaccomplished with a higher clock rate or a more accurate clock in acontroller or driver. In one embodiment, the jitter spec is less thanthe time it takes an image sensor to read out one line (e.g., row orcolumn). For example, a CMOS array may readout pixels from the arrayline by row or column. In one embodiment, the jitter spec is less thanthe time it takes an image sensor to read out a single pixel. In oneembodiment, the jitter spec may be less than or equal to 10% to 25% ofthe readout period of the pixel array of the image sensor, or the timeit takes an image sensor to read out all the lines in the pixel array.In one embodiment, the jitter spec may be less than or equal to about10% to about 25% of the readout period of the pixel array of the imagesensor, or the time it takes an image sensor to read out all the linesin the pixel array. For example, in a pixel array that comprises a totalof 400 lines, the jitter spec is less than or equal to the time that isrequired to read out 40-100 lines of the 400 lines in the pixel array.Thus, the amount of variation in the light captured may be low enough toreduce image flicker and/or provide as much light as possible betweenreadout periods. For example, with a low jitter spec a control signal toturn off light emission may be provided close to the time at which areadout period begins. The reduced jitter spec and tolerance of thedriver thus solves the problem of untoleranced driving causingartifacting in a light pulsing scheme.

In one embodiment, a camera control unit (CCU) may provide signals to acontroller or light source to avoid overlapping into a readout period.For example, the CCU may determine a timing for sending a signal to acontroller or light source to avoid overlapping into the readout ofpixels that are not optical black pixels within the pixel array. In oneembodiment, the CCU may maximize the amount of time light is emittedwithout overlapping into the readout period.

FIG. 3 illustrates a cross section of a fiber bundle 300 having sevenfibers. The number of fibers is illustrative as any number of fibers maybe used. In one embodiment, the number of fibers is limited to reduce across sectional area of the fiber bundle. The number of fibers may bebased on a number of fibers that provide sufficient light dispersionwhile allowing for a small cross sectional area since the crosssectional area of an endoscopic lumen may be of importance. In oneembodiment, the fiber bundle may include from 2 to 150 fibers. A smallernumber of fibers may reduce expense and/or the required cross sectionalarea needed to carry a fiber bundle. However, increased numbers offibers improves redundancy. In one embodiment, the fiber bundle includes5-100 fibers. In one embodiment, the fiber bundle includes 5-50 fibers.In one embodiment, the fiber bundle includes 7-15 fibers. In oneembodiment, the fiber bundle includes 7 fibers. When a smaller number offibers is used, it may be desirable that each fiber receives the sameamount of light and/or the same amount of a specific color of light. Forexample, if light provided to the fiber bundle is mostly in the center,the center fiber may receive the majority of the electromagnetic energy.Thus, an imaging scene may be unevenly illuminated by color orbrightness.

FIG. 3 illustrates a center fiber 302 having more or most of theelectromagnetic energy. Additionally, if more light enters into onefiber than another, the overall amount of light (power) that can becarried in the fibers is reduced. For example, a fiber may have aburn-out limit or other limit that may result in the fiber melting orotherwise becoming inoperative if light above a certain energy level orintensity is provided to the fiber. Thus, if light is more evenlydistributed across fibers, an increase in power and illumination at ascene is possible.

In one embodiment, a light source that provides light to the fiberbundle 300 may mix one or more colors of light before providing to afiber bundle. For example, the light source 102, jumper waveguide 106,and/or coupler 108 may evenly mix light before providing the light tothe lumen waveguide 110. In one embodiment, the light source may includea first laser emitter that emits light of a first wavelength and asecond laser emitter that emits light of a second wavelength. The lightsource may mix the light by having light from the first laser emitterand the second laser emitter enter the jumper waveguide 106 (or otherwaveguide) at a same or substantially same angle. A same orsubstantially same angle may be achieved by positioning light sources ata same angle as each other. In one embodiment, a dichroic mirror mayallow for a same or substantially same angle by reflecting light of onecolor (or wavelength) while being transparent to another color (orwavelength) of light. In one embodiment, the light source may include adiffuser, mixing rod, lens, or other optical element to mix light beforeentry into a fiber optic cable, such as the lumen waveguide 110 of FIG.1.

In one embodiment, a light source that provides light to the fiberbundle 300 may provide an evenly distributed light intensity to awaveguide. In one embodiment, the peak intensity of light within aregion where light is collected for a waveguide may be substantially thesame as or close to the average intensity of light over the region. Forexample, the light provided to a collection region may have a top hatprofile so that each fiber collects and/or receives a same or similarintensity of light. The light source may provide or approximate a tophat profile by providing laser light at an angle to a surface of acollection region. For example, emitters may have a Gaussian or othernon-constant intensity profile. By angling the emitters in relation to acollection region, the Gaussian profile may be flattened out into a moreconstant or top-hat profile. The top hat profile may also be generatedusing lenses, diffusers, mixing rods, or the like.

FIG. 4 graphically illustrates a top hat profile 402 and a Gaussianprofile 404. The horizontal axis represents horizontal distance and thevertical axis represents light intensity. The lines 406 represent theboundaries or width of a collection region or fiber bundle. Line 408represents a burn-out level for a fiber or other waveguide. For example,the line 408 may represent a burn-out level for a plastic fiber. Withthe Gaussian profile 404, most of the light will end up in a centerfiber. Because most of the light is in the center fiber other fibers maybe far below the burn-out level. With the top-hat profile, all fiberswill be at the same level, whether it be near the burn-out level orbelow it. For example, with the top hat profile 402, the total amount ofenergy carried by a fiber bundle may be significantly increased becauseeach bundle can be placed near burn-out without risking burn-out of anysingle fiber. For example, with the Gaussian profile 404 an increase inthe total amount of power could lead to a center fiber significantlyexceeding the burn-out level with the edge fibers far below the burn-outlevel. FIG. 4 clearly illustrates that more power can be provided beforeany of the individual fibers reach burn-out using a top-hat profile. Forexample, the Gaussian profile 404 and the top-hat profile 402 mayprovide the same amount of wattage to the fiber bundle, while thetop-hat profile 402 can still be increased significantly before reachingburn-out. Thus, a significant improvement in the total amount of lightdelivered using plastic fibers can be achieved. In some cases a 50% orgreater increase of wattage carried by a fiber bundle may be achieved.In an embodiment, the plastic fibers may have a burn-out energy levelfor light/electromagnetic energy emitted by the one or more emittersabove which damage to the plastic fibers may occur, wherein the lightenergy is spread out across the plurality of plastic fibers to allow agreater amount of energy to be carried by a fiber bundle including theplastic fibers without reaching the burn-out energy level in any of theplastic fibers.

In one embodiment, mixing and a top-hat profile may be implemented by alight source for use with plastic fiber bundles. For example, the lightsource 102 and/or the jumper waveguide 106 may not include plasticwaveguides. However, the light source 102 may provide mixing and atop-hat profile to allow for use with a fiber bundle, such as a plasticfiber bundle, at the lumen waveguide 110. In one embodiment, the use ofmixing and/or a top-hat profile may allow for greater power delivery inview of losses that may be incurred when moving the light betweendifferent materials (e.g., from a diffuser to a glass fiber, to aplastic fiber, and/or back to a glass fiber or diffuser). For example,the greater power delivery may offset losses in previous or subsequenttransitions so that sufficient light can still be delivered to a scenefor illumination.

FIGS. 5-7 are schematic block diagrams illustrating a light source 500having a plurality of emitters. With regard to FIG. 5, the emittersinclude a first emitter 502, a second emitter 504, and a third emitter506. The emitters 502, 504, and 506 may include one or more laseremitters that emit light having different wavelengths. For example, thefirst emitter 502 may emit a wavelength that is consistent with a bluelaser, the second emitter 504 may emit a wavelength that is consistentwith a green laser, and the third emitter 506 may emit a wavelength thatis consistent with a red laser. The emitters 502, 504, 506 emit laserstoward a collection region 508, which may be the location of awaveguide, lens, or other optical component for collecting and/orproviding light to a waveguide, such as the jumper waveguide 106 orlumen waveguide 110 of FIG. 1.

In the embodiment of FIG. 5, the emitters 502, 504, 506 each deliverlaser light to the collection region 508 at different angles. Thevariation in angle can lead to variations where electromagnetic energyis located in an output waveguide. For example, if the light passesimmediately into a fiber bundle (glass or plastic) at the collectionregion 508, the varying angles may cause different amounts of light toenter different fibers. For example, the angle may result in intensityvariations across the collection region 508. Furthermore, light from thedifferent emitters would not be homogenously mixed so some fibers mayreceive different amounts of light of different colors. As discussedpreviously, variation in the color or intensity of light in differentfibers can lead to non-optimal illumination of a scene. For example,variations in delivered light or light intensities may result at thescene and captured images.

In one embodiment, an intervening optical element may be placed betweena fiber bundle and the emitters 502, 504, 506 to mix the differentcolors (wavelengths) of light before entry into the fibers. Exampleintervening optical elements include a diffuser, mixing rod, one or morelenses, or other optical components that mix the light so that a givenfiber receive a same amount of each color (wavelength). For example,each fiber in the fiber bundle may have a same color. This mixing maylead to the same color in each fiber but may, in some embodiments, stillresult in different total brightness delivered to different fibers. Inone embodiment, the intervening optical element may also spread out oreven out the light over the collection region so that each fiber carriesthe same total amount of light (e.g., see the top hat profile 402 ofFIG. 4).

Although the collection region 508 is represented as a physicalcomponent in FIG. 5, the collection region 508 may simply be a regionwhere light from the emitters 502, 504, and 506 is delivered. In somecases, the collection region 508 may include an optical component suchas a diffuser, mixing rod, lens, or any other intervening opticalcomponent between the emitters 502, 504, 506 and an output waveguide.

FIG. 6 illustrates an embodiment of a light source 500 with emitters502, 504, 506 that provide light to the collection region 508 at thesame or substantially same angle. The light is provided at an anglesubstantially perpendicular to the collection region 508. The lightsource 500 includes a plurality of dichroic mirrors including a firstdichroic mirror 602, a second dichroic mirror 604, and a third dichroicmirror 606. The dichroic mirrors 602, 604, 606 include mirrors thatreflect a first wavelength of light, but transmit (or are transparentto) a second wavelength of light. For example, the third dichroic mirror606 may reflect blue laser light provided by the third emitter, whilebeing transparent to the red and green light provided by the firstemitter 502 and the second emitter 504, respectively. The seconddichroic mirror 604 may be transparent to red light from the firstemitter 502, but reflective to green light from the second emitter 504.

Because the dichroic mirrors allow other wavelengths to transmit or passthrough, each of the wavelengths may arrive at the collection region 508from a same angle and/or with the same center or focal point. Providinglight from the same angle and/or same focal/center point cansignificantly improve reception and color mixing at the collectionregion 508. For example, a specific fiber may receive the differentcolors in the same proportions they were transmitted/reflected by theemitters 502, 504, 506 and mirrors 602, 604, 606. Light mixing may besignificantly improved at the collection region compared to theembodiment of FIG. 5. In one embodiment, any optical componentsdiscussed herein may be used at the collection region 508 to collectlight prior to providing it to a fiber bundle.

FIG. 7 illustrates an embodiment of a light source 500 with emitters502, 504, 506 that also provide light to the collection region 508 atthe same or substantially same angle. However, the light incident on thecollection region 508 is offset from being perpendicular. Angle 702indicates the angle offset from perpendicular (i.e., a non-perpendicularangle). In one embodiment, the laser emitters 502, 504, 506 may havecross sectional intensity profiles that are Gaussian. As discussedpreviously, improved distribution of light energy between fibers may beaccomplished by creating a more flat or top-hat shaped intensityprofile. In one embodiment, as the angle 702 is increased, the intensityacross the collection region 508 approaches a top hat profile. Forexample, a top-hat profile may be approximated even with a non-flatoutput beam by increasing the angle 702 until the profile issufficiently flat.

The top hat profile may also be accomplished using one or more lenses,diffusers, mixing rods, or any other intervening optical componentbetween the emitters 502, 504, 506 and an output waveguide or fiberoptic bundle.

FIG. 8 is a schematic side view illustrating light output from anoptical fiber 802 in comparison to a camera field of view. In oneembodiment, a plastic fiber has a numerical aperture of 0.63 with afield of view of 100 degrees, as indicated by dashed line 806, and aglass fiber has a numerical aperture of 0.87 with a field of view of 120degrees, as indicated by solid line 804. However, light emitted withinthe field of view has an approximately Gaussian profile within a lightcone that is less than the field of view. For example, nearly all thelight for a plastic fiber may be within a cone of 80 degrees, asindicated by dotted line 808. Thus, a center region of an image may betoo bright while the edges are too dark. This problem is worse whenplastic fiber is used, for example, when the lumen waveguide includesplastic fibers.

In one embodiment, a more uniform distribution of light can be achievedby aiming the ends of the fibers where light exits the fiber bundle.FIG. 9 is a schematic diagram illustrating aiming of fibers, such asplastic fibers, of a fiber bundle 902 at an output end. Aiming thefibers away from a center may broaden the cone in a field of view withno light loss at the output. An end of each fiber may be held in adesired position to distribute the light where the combination of lightcones from the fibers provides a more even illumination. A fiber bundle902 includes a plurality of fibers and lines 904 that indicate theorientation of cones output by the individual fibers. For example, afixture may be used to hold the ends of fibers at a physical mold, sheetwith holes, or the like that may hold the fibers in the desiredorientation. The fibers may be oriented in an optimal orientation foreven illumination of a scene. The tips of the fibers in the fiber bundlemay be located near a scope tip and may be pointed to spread lightaround a region centered on the focal point or camera lens axis.

FIG. 10 is a schematic diagram illustrating output of light using glassfibers 1004. Specifically, a lumen waveguide may include plastic fibers1002 and then transition to glass fibers 1004 at or near an output. Theglass fibers 1004 generally have a higher numerical aperture and a widerfield of view than plastic fibers. Thus, a wider and more evendistribution of light energy may be achieved. The light travelingthrough the plastic fibers 1002 may be guided to the glass fibers 1004via connector 1006 or connecting waveguide. The light output from theglass fibers 1004 may have a wide light cone 1008, as compared to thelight cone for a plastic fiber, for improved illumination of a scene.The coupling may occur in a hand piece or in a lumen of the arthroscope.For example, the connector 1006 may be positioned in a hand piece or ina lumen to limit the amount of glass fibers 1004 used. Moving fromplastic fiber through a taper in the hand piece or the lumen to a glassfiber that has a higher numerical aperture (e.g., NA of 0.84-0.87) mayresult is the same field of view as a conventional athroscope. However,light loss may be significant, such as about 25% compared to the aimingembodiment, which experiences no light loss at the output.

FIG. 11 is a schematic diagram illustrating output of light using adiffuser 1104 at an output. Specifically, a lumen waveguide may includeplastic fibers 1102 and then transition to the diffuser 1104 at or nearan output. The diffuser 1104 may include any type of optical diffuser,mixing rod, or the like. Example diffusers include a holographicdiffuser from Edmund®, Luminit®, or an RPC Engineered Diffuser™. Thediffuser at the output can produce an even larger angle than the use ofclass fibers, but is less efficient, such as about 40-60% efficientversus the aiming embodiment.

In one embodiment, plastic fibers 1002 are significantly cheaper thanglass fibers 1004. The reduced price can lead to significantly cheaperillumination system and endoscopic system. Because glass may only beused for a short distance near an output, or not at all, a significantcost savings may be achieved. For example, this cost savings of plasticmay still be achieved in the embodiment of FIG. 10 because the amount(length and number) of glass fibers 1004 is significantly reduced.Although significant amounts of light may be lost in the transition fromplastic to glass (e.g., 25% loss), or using a diffuser (e.g., 40-60%light loss) the usage of the top-hat profile or other methods herein maystill allow for sufficient lighting to be delivered to an imaging regionbecause a greater amount of light may be carried in the fibers whencompared to other methods or devices. For example, the other methods anddevices discussed herein in relation may be used in combination toprovide an overall cheaper endoscopic illumination system whilemaintaining sufficient lighting for high image quality. In oneembodiment, a portion of the endoscopic system, such as the lumenwaveguide 110 of FIG. 1, may be disposable or reposable.

It should be understood that embodiments for outputting light mayinclude a combination of the embodiments of FIGS. 9-11. For example,plastic fibers may be transitioned to glass fibers and the glass fibersmay be aimed to provide more uniform and improved illumination.

FIG. 12 is a schematic flow chart diagram illustrating an example method1200 for providing light to an imaging scene in a light deficientenvironment. The method 1200 may be performed by an illumination system,such as the system 100 of FIG. 1.

The method 1200 begins and an image sensor generates and reads out at1202 pixel data from an image sensor for an image based on lightreceived by the image sensor, wherein a time length for reading out aline of pixel data includes a line readout length. An emitter emits at1204 light for illumination of a scene observed by the image sensor. Adriver drives at 1206 emission by the emitter, wherein the driverincludes a jitter specification of less than or equal to the linereadout length. A controller controls at 1208 the driver to drive theemitter to generate pulses of light between readout periods for theimage sensor.

FIG. 13 is a schematic flow chart diagram illustrating an example method1300 for providing light to an imaging scene in a light deficientenvironment. The method 1300 may be performed by an illumination system,such as the system 100 of FIG. 1.

The method 1300 begins and a first emitter and second emitter emit at1302 light including a first wavelength and a second wavelength. Aplurality of optical fibers guides at 1304 light generated by the firstemitter and the second emitter to a scene in an endoscopic environment.The plurality of optical fibers receives at 1306 a substantially equalamount of light (mixed light) from the first emitter and the secondemitter at each optical fiber of the plurality of optical fibers.

FIG. 14 is a schematic flow chart diagram illustrating an example method1400 for providing light to an imaging scene in a light deficientenvironment. The method 1400 may be performed by an illumination system,such as the system 100 of FIG. 1.

The method 1400 begins and one or more emitters emit light at 1402. Aplurality of optical fibers guides at 1404 light from the one or moreemitters to an endoscopic environment. Each optical fiber of theplurality of optical fibers receives at 1406 a substantially equalamount of light from the one or more emitters.

FIG. 15 is a schematic flow chart diagram illustrating an example method1500 for providing light to an imaging scene in a light deficientenvironment. The method 1500 may be performed by an illumination system,such as the system 100 of FIG. 1.

The method 1500 begins and a plurality of optical fibers guides at 1502light to an endoscopic scene. A light spreading member spreads at 1504light to increasing one or more of a uniformity and area over whichlight exiting the waveguide is distributed.

In one embodiment, a single fiber may replace a fiber bundle (such as afiber bundle as in any of FIG. 3, 9, 10, or 11). The single fiber may belarger and may be able to handle a larger amount of power than a bundleof smaller fibers for the same occupied cross-sectional area. The singlefiber may extend from a console and through a lumen to provide light toan interior of a body, or other light deficiency environment. Forexample, the single fiber may operate as a lumen waveguide that extendsfrom a light source 102 or jumper waveguide 106 and through a lumen 112(see FIG. 1). Light may be provided by the light source 102 directly tothe single fiber with a top-hat profile.

Because a plastic fiber may only have a numerical aperture of 0.63 or0.65, most of the light may only come out at an angle of 70 or 80degrees. At an output of the single fiber (e.g., at a distal end of alumen), a diffuser may be positioned to spread output light and create amore even illumination within a field-of-view of a camera that capturesimages. In one embodiment, the type of diffuser or the presence of adiffuser may be based on the field-of-view used by the camera during theexamination. For example, laparoscopic procedures or examinations mayallow for more narrow fields of view (such as 70 degrees) whilearthroscopic procedures or examinations may use broader fields of view(such as 110 degrees). Thus, a diffuser may be used for arthroscopicexaminations or lumens while a diffuser may be absent for laparoscopicexaminations or lumens. For example, light may be emitted from the fiberinto the interior environment without passing through a diffuser in thelaparoscopic examination or lumen.

FIG. 16 is a schematic diagram illustrating a single optical fiber 1602outputting via a diffuser 1604 at an output. In one embodiment, theoptical fiber 1602 may have a diameter of 500 microns and have anumerical aperture of 0.65 and emits a light cone 1606 of about 70 or 80degrees without a diffuser 1604. With the diffuser, the light cone 1606may have an angle of about 110 or 120 degrees.

FIG. 17 is a schematic diagram illustrating an example embodiment of asystem 1700 for providing illumination to a light deficient environment,such as for endoscopic imaging. The system 1700 includes a light source102, a controller 104, a lumen waveguide 1702, a lumen 112, and an imagesensor 114 with accompanying optical components. In one embodiment, thelight source 102 and/or the controller 104 may be located in a consoleor camera control unit 1704 to which an endoscope comprising the lumen112 may be attached.

The light source 102 generates light or other electromagnetic energythat is provided into the lumen waveguide 1702 using any embodiment ormethod discussed herein. The electromagnetic energy travels through thelumen waveguide 1702 to illuminate a scene at a distal end of the lumen112. The lumen 112 may be inserted into a patient's body for imaging,such as during a procedure or examination. The light is output asillustrated by dashed lines 1706. A scene illuminated by the light maybe captured using the image sensor 114 and displayed for a doctor orsome other medical personnel.

In one embodiment, the lumen waveguide 1702 may include a single plasticoptical fiber of about 500 microns. The plastic fiber may be low costbut the width may allow the fiber to carry a sufficient amount of lightto a scene, with coupling, diffuser, or other losses. The lumenwaveguide 110 includes a plurality of optical fibers. The lumenwaveguide 1702 may receive light directly from the light source or via ajumper waveguide (e.g., see the jumper waveguide 106 of FIG. 1). Adiffuser may be used to broaden the light output 1706 for a desiredfield of view of the image sensor 114 or other optical components.

Examples

The following examples pertain to further embodiments.

Example 1 is an endoscopic system that includes an image sensor. Theimage sensor includes a pixel array and is configured to generate andread out pixel data for an image based on electromagnetic radiationreceived by the pixel array. The pixel array includes a plurality oflines for reading out pixel data, wherein a time length for reading outall the plurality of lines of pixel data in the pixel array comprises areadout period. The endoscopic system includes an emitter configured toemit electromagnetic radiation for illumination of a scene observed bythe image sensor. The endoscopic system includes an electromagneticradiation driver configured to drive emissions by the emitter, whereinthe electromagnetic radiation driver includes a jitter specificationthat is less than or equal to about 10% to about 25% percent of thereadout period of the pixel array of the image sensor.

In Example 2, the endoscopic system of Example 1 further includes acontroller configured to control the electromagnetic radiation driver todrive the emitter to generate one or more pulses of electromagneticradiation between a readout period for the image sensor.

In Example 3, the controller of Example 2 is further configured todetermine a timing for signals to the electromagnetic radiation driverto pulse electromagnetic radiation for illuminating a scene in anendoscopic environment without overlapping into the readout period forthe image sensor.

In Example 4, the readout period as in any of Examples 2-3 starts afterreading out a row or column of optical black pixels and the readoutperiod ends with the readout of a row or column of optical black pixels.

In Example 5, a time length for reading out pixel data for a singlepixel in any of Examples 1-5 is a pixel readout length, wherein theelectromagnetic radiation driver jitter specification is less than orequal to the pixel readout length of the image sensor.

In Example 6, the image sensor as in any of Examples 1-5 includes acomplementary metal-oxide-semiconductor (CMOS) image sensor.

In Example 7, the CMOS image sensor as in any of Examples 1-6 ismonochromatic.

In Example 8, the CMOS image sensor as in any of Examples 1-6 is colorfiltered.

In Example 9, the emitter as in any of Examples 1-8 includes one or morepulsing lasers.

In Example 10, the electromagnetic radiation driver jitter specificationas in any of Examples 1-9 is about 1 microsecond or less.

In Example 11, the electromagnetic radiation driver jitter specificationas in any of Examples 1-9 is about 50 nanoseconds or less.

In Example 12, the image sensor as in any of Examples 1-5 includes acharge-coupled device (CCD) image sensor.

In Example 13, the CCD image sensor as in any of Examples 1-5 and 12 ismonochromatic.

In Example 14, the CCD image sensor as in any of Examples 1-5 and 12 iscolor filtered.

In Example 15, the emitter as in any of Examples 1-14 emits a pluralityof pulses of electromagnetic radiation, wherein each successive pulse isa different range of wavelengths of electromagnetic energy.

In Example 16, the system as in any of Examples 1-15 includes anendoscope comprising a lumen with a distal end, wherein the image sensoris located within the distal end of the lumen of the endoscope.

In Example 17, the system as in any of Examples 1-4 and 6-16 wherein atime length for reading out a single line of pixel data comprises a linereadout length, wherein the jitter specification is less than or equalto the line readout length.

Example 18 is a method for endoscopic imaging that may be used alone orwith any of Examples 1-17. The method includes generating and readingout pixel data for an image based on electromagnetic radiation receivedby a pixel array of an image sensor. The pixel array comprises aplurality of lines for reading out pixel data, and wherein a time lengthfor reading out all the plurality of lines of pixel data in the pixelarray comprises a readout period. The method also includes emittingelectromagnetic radiation using an emitter. The method further includesilluminating a scene observed by the image sensor with theelectromagnetic radiation emitted from the emitter. The method furtherincludes driving emission by the emitter using an electromagneticradiation driver, the electromagnetic radiation driver comprising ajitter specification that is less than or equal to about 10% to about25% percent of the readout period of the pixel array of the imagesensor.

In Example 19, the method as in Example 18 further includes controllingthe electromagnetic radiation driver to drive the emitter to generateone or more pulses of electromagnetic radiation between a readout periodfor the image sensor using a controller.

In Example 20, the method as in any of Examples 18 and 19 wherein thecontroller determines a timing for signals to the electromagneticradiation driver to pulse electromagnetic radiation for illuminating ascene in an endoscopic environment without overlapping into the readoutperiod for the image sensor.

In Example 21, the method as in any of Examples 18-20 wherein thereadout period starts after reading out a row or column of optical blackpixels and the readout period ends with the readout of a row or columnof optical black pixels.

In Example 22, the method as in any of Examples 18-21 wherein a timelength for reading out pixel data for a single pixel is a pixel readoutlength, wherein the jitter specification is less than or equal to thepixel readout length of the image sensor.

In Example 23, the method as in any of Examples 18-22 wherein the imagesensor comprises a complementary metal-oxide-semiconductor (CMOS) imagesensor.

In Example 24, the method as in any of Examples 18-23 wherein the CMOSimage sensor is monochromatic.

In Example 25, the method as in any of Examples 18-23 wherein the CMOSimage sensor is color filtered.

In Example 26, the method as in any of Examples 18-25 wherein theemitter comprises one or more pulsing lasers.

In Example 27, the method as in any of Examples 18-26 wherein theelectromagnetic radiation driver jitter specification is about 1microsecond or less.

In Example 28, the method as in any of Examples 18-27 wherein theelectromagnetic radiation driver jitter specification is about 50nanoseconds or less.

In Example 29, the method as in any of Examples 18-22 and 26-28 whereinthe image sensor is a charge-coupled device (CCD) image sensor.

In Example 30, the method as in any of Examples 18-22 and 26-29 whereinthe CCD image sensor is monochromatic.

In Example 31, the method as in any of Examples 18-22 and 26-29 whereinthe CCD image sensor is color filtered.

In Example 32, the method as in any of Examples 18-31 further includesemitting a plurality of pulses of electromagnetic radiation with theemitter, wherein each successive pulse is a different range ofwavelengths of electromagnetic energy.

In Example 33, the method as in any of Examples 18-32 wherein the imagesensor is located within a distal end of a lumen of an endoscope.

In Example 34, the method as in any of Examples 18-21 and 23-33 whereina time length for reading out a single line of pixel data comprises aline readout length, wherein the jitter specification is less than orequal to the line readout length.

Example 35 is an endoscopic light source that may be used alone or withany of Examples 1-34. The endoscopic light source includes a firstemitter which emits light of a first wavelength at a first dichroicmirror which reflects the light of the first wavelength to a pluralityof optical fibers. The endoscopic light source also includes a secondemitter which emits light of a second wavelength at a second dichroicmirror which reflects the light of the second wavelength to theplurality of optical fibers. The first dichroic mirror is transparent tothe light of the second wavelength.

In Example 36, the first dichroic mirror as in Example 35 reflects lightof the first wavelength into the plurality of optical fibers at an anglethat is substantially perpendicular to the first emitter.

In Example 37, the second dichroic mirror as in any of Examples 35-36reflects light of the second wavelength into the plurality of opticalfibers through the first dichroic mirror at an angle that issubstantially perpendicular to the second emitter.

In Example 38, the first dichroic mirror as in any of Examples 35-37reflects light of the first wavelength into the plurality of opticalfibers at an angle that is offset from perpendicular.

In Example 39, the second dichroic mirror as in any of Examples 35-38reflects light of the second wavelength into the plurality of opticalfibers at an angle through the first dichroic mirror at an angle that isoffset from perpendicular.

In Example 40, the endoscopic light source as in any of Examples 35-39further includes a third emitter which emits light of a third wavelengthat a third dichroic mirror which reflects the light of the thirdwavelength to the plurality of optical fibers.

In example 41, the first dichroic mirror and the second dichroic mirroras in any of Examples 35-40 are transparent to the light of the thirdwavelength.

In Example 42, the third dichroic mirror as in any of Examples 35-41reflects light of the third wavelength into the plurality of opticalfibers at an angle that is substantially perpendicular to the thirdemitter.

In Example 43, the third dichroic mirror as in any of Examples 35-42reflects light of the third wavelength into the plurality of opticalfibers at an angle that is offset from perpendicular.

In Example 44, the light of the third wavelength reflected by the thirddichroic mirror as in any of Examples 35-43 is reflected into theplurality of optical fibers through the first dichroic mirror.

In Example 45, the light of the third wavelength reflected by the thirddichroic mirror as in any of Examples 35-43 is reflected into theplurality of optical fibers through the second dichroic mirror.

In Example 46, endoscopic light source as in any of Examples 35-45further includes an intervening optical component, wherein the light ofthe first wavelength and the light of the second wavelength pass throughthe intervening optical component before entering the plurality ofoptical fibers.

In Example 47, the intervening optical component as in any of Examples35-46 includes a diffuser.

In Example 48, the intervening optical component as in any of Examples35-46 includes a mixing rod.

In Example 49, the plurality of optical fibers as in any of Examples35-48 includes a plurality of plastic optical fibers and wherein theintervening optical component includes a plurality of glass fibers.

In Example 50, the endoscopic light source as in any of Examples 35-49further includes a third emitter which emits light of a third wavelengththat is reflected by a third dichroic mirror through the first dichroicmirror and the second dichroic mirror, wherein the light of the firstwavelength, the light of the second wavelength, and the light of thethird wavelength are mixed by the intervening optical component toprovide substantially homogenously colored light to each of theplurality of optical fibers.

In Example 51, the first emitter as in any of Examples 35-50 includes afirst laser emitter and the second emitter includes a second laseremitter.

In Example 52, the third emitter as in any of Examples 35-51 includes athird laser emitter.

In Example 53, the plurality of optical fibers as in any of Examples35-52 includes between 2 and 150 fibers.

In Example 54, one of the first emitter, the second emitter, and thethird emitter as in any of Examples 35-53 emits a red light and whereinone of the first emitter, the second emitter, and the third emitteremits a green light, and wherein one of the first emitter, the secondemitter, and the third emitter emits a blue light.

Example 55 is an endoscopic system that may be used alone or with any ofExamples 1-54. The endoscopic system may include a single optical fiber.The endoscopic system may include a light source which transmits lightinto the single optical fiber. Further, the endoscopic system mayinclude an image sensor disposed at a distal end of the single opticalfiber.

In Example 56, the system as in Example 55 includes a diffuser disposedat a distal end of the single optical fiber.

In Example 57, the diffuser as in any of Examples 55-56 provides a lightcone having an angle of between 110 degrees and 120 degrees.

In Example 58, the single optical fiber as in any of Examples 55-57provides a light cone of between 70 degrees and 80 degrees.

In Example 59, the single optical fiber as in any of Examples 55-58 is aplastic optical fiber.

In Example 60, the single optical fiber as in any of Examples 55-59 hasa numerical aperture of 0.63.

In Example 61, the single optical fiber as in any of Examples 55-59 hasa numerical aperture of 0.65.

In Example 62, the single optical fiber as in any of Examples 55-61 hasa diameter of between 475 and 525 microns.

In Example 63, the system as in any of Examples 55-62 further includes alight source controller.

In Example 64, the light source and the light source controller as inany of Examples 55-63 are located in a camera control unit.

In Example 65, the single optical fiber as in any of Examples 55-64 isattached to a plurality of optical fibers between the distal end of thesingle optical fiber and an endoscope.

In Example 66, the plurality of optical fibers as in any of Examples55-64 is attached to the camera control unit through the endoscope.

In Example 67, light or other electromagnetic energy as in any ofExamples 55-65 is transmitted through the single optical fiber toilluminate a scene at a distal end of the single optical fiber.

In Example 68, the single optical fiber as in any of Examples 55-66 isattached to an endoscope.

Examples 69 is an endoscope that may be used alone or with any ofExamples 1-68. The endoscope may include a single optical fiber, animage sensor disposed at a distal end of the single optical fiber, and adiffuser disposed at a distal end of the single optical fiber.

In Example 70, the diffuser as in Example 69 provides a light cone ofbetween 110 and 120 degrees at the distal end of the single opticalfiber.

In Example 71, the endoscope as in any of Examples 69-70 includes alight source and a light source controller.

In Example 72, the light source and the light source controller as inany of Examples 69-71 are located in a camera control unit.

In Example 73, the single optical fiber as in any of Examples 69-72 isattached to a plurality of optical fibers between the distal end of thesingle optical fiber and the light source.

In Example 74, light or other electromagnetic energy as in any ofExamples 69-73 is transmitted through the single optical fiber toilluminate a scene at a distal end of the single optical fiber.

In Example 75, the plurality of optical fibers as in Examples 73includes from 5 to 100 fibers.

Example 76 is an apparatus including means to perform a method orimplement an apparatus as in of any of Examples 1-75.

Example 77 is an embodiment comprising any combination of elements,functionality, or devices of Examples 1-76.

Various techniques, or certain aspects or portions thereof, may take theform of program code (i.e., instructions) embodied in tangible media,such as floppy diskettes, CD-ROMs, hard drives, a non-transitorycomputer readable storage medium, or any other machine readable storagemedium wherein, when the program code is loaded into and executed by amachine, such as a computer, the machine becomes an apparatus forpracticing the various techniques. In the case of program code executionon programmable computers, the computing device may include a processor,a storage medium readable by the processor (including volatile andnon-volatile memory and/or storage elements), at least one input device,and at least one output device. The volatile and non-volatile memoryand/or storage elements may be a RAM, an EPROM, a flash drive, anoptical drive, a magnetic hard drive, or another medium for storingelectronic data. One or more programs that may implement or utilize thevarious techniques described herein may use an application programminginterface (API), reusable controls, and the like. Such programs may beimplemented in a high-level procedural or an object-oriented programminglanguage to communicate with a computer system. However, the program(s)may be implemented in assembly or machine language, if desired. In anycase, the language may be a compiled or interpreted language, andcombined with hardware implementations.

It should be understood that many of the functional units described inthis specification may be implemented as one or more components, whichis a term used to more particularly emphasize their implementationindependence. For example, a component may be implemented as a hardwarecircuit comprising custom very large scale integration (VLSI) circuitsor gate arrays, off-the-shelf semiconductors such as logic chips,transistors, or other discrete components. A component may also beimplemented in programmable hardware devices such as field programmablegate arrays, programmable array logic, programmable logic devices, orthe like.

Components may also be implemented in software for execution by varioustypes of processors. An identified component of executable code may, forinstance, comprise one or more physical or logical blocks of computerinstructions, which may, for instance, be organized as an object, aprocedure, or a function. Nevertheless, the executables of an identifiedcomponent need not be physically located together, but may comprisedisparate instructions stored in different locations that, when joinedlogically together, comprise the component and achieve the statedpurpose for the component.

Indeed, a component of executable code may be a single instruction, ormany instructions, and may even be distributed over several differentcode segments, among different programs, and across several memorydevices. Similarly, operational data may be identified and illustratedherein within components, and may be embodied in any suitable form andorganized within any suitable type of data structure. The operationaldata may be collected as a single data set, or may be distributed overdifferent locations including over different storage devices, and mayexist, at least partially, merely as electronic signals on a system ornetwork. The components may be passive or active, including agentsoperable to perform desired functions.

Reference throughout this specification to “an example” means that aparticular feature, structure, or characteristic described in connectionwith the example is included in at least one embodiment of the presentdisclosure. Thus, appearances of the phrase “in an example” in variousplaces throughout this specification are not necessarily all referringto the same embodiment.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based onits presentation in a common group without indications to the contrary.In addition, various embodiments and examples of the present disclosuremay be referred to herein along with alternatives for the variouscomponents thereof. It is understood that such embodiments, examples,and alternatives are not to be construed as de facto equivalents of oneanother, but are to be considered as separate and autonomousrepresentations of the present disclosure.

Although the foregoing has been described in some detail for purposes ofclarity, it will be apparent that certain changes and modifications maybe made without departing from the principles thereof. It should benoted that there are many alternative ways of implementing both theprocesses and apparatuses described herein. Accordingly, the presentembodiments are to be considered illustrative and not restrictive.

Those having skill in the art will appreciate that many changes may bemade to the details of the above-described embodiments without departingfrom the underlying principles of the disclosure.

What is claimed is:
 1. An endoscopic light source, comprising: a firstemitter which emits light of a first wavelength into a waveguidecomprising a plurality of optical fibers at a first angle; a secondemitter which emits light of a second wavelength into the plurality ofoptical fibers of the waveguide at a second angle; and a third emitterwhich emits light of a third wavelength into the waveguide comprisingthe plurality of optical fibers at a third angle; wherein the firstangle is different from the second angle and the third angle isdifferent from the second angle and the first angle; and wherein thefirst emitter and the second emitter are oriented at the first angle andthe second angle, respectively, relative to a surface of a collectionregion of the waveguide such that the first emitter and the secondemitter provide a same or similar intensity of light to each fiber ofthe plurality of optical fibers of the waveguide.
 2. The endoscopiclight source of claim 1, wherein one or more of the first angle and thesecond angle are offset from perpendicular to the plurality of opticalfibers of the waveguide.
 3. The endoscopic light source of claim 2,wherein the first angle and the second angle are offset fromperpendicular to the plurality of optical fibers of the waveguide. 4.The endoscopic light source of claim 1, further comprising: anintervening optical component disposed between the waveguide and thefirst and second emitters, wherein the intervening optical componentmixes the light of the first wavelength with the light of the secondwavelength before the lights enter the waveguide.
 5. The endoscopiclight source of claim 4, wherein the intervening optical componentincludes a diffuser or a mixing rod.
 6. The endoscopic light source ofclaim 4, wherein the plurality of optical fibers includes a plurality ofplastic optical fibers and wherein the intervening optical componentincludes a plurality of glass fibers.
 7. The endoscopic light source ofclaim 1, wherein one or more of the first angle, the second angle, andthe third angle are offset from perpendicular to the waveguide.
 8. Theendoscopic light source of claim 1, wherein two or more of the firstangle, the second angle, and the third angle are offset fromperpendicular to the waveguide.
 9. The endoscopic light source of claim1, wherein the first angle, the second angle, and the third angle areoffset from perpendicular to the waveguide.
 10. The endoscopic lightsource of claim 1, further comprising: an intervening optical componentdisposed between the waveguide and the first, second, and thirdemitters, wherein the optical element mixes the light of the firstwavelength with the light of the second wavelength and the light of thethird wavelength before the lights enter the waveguide.
 11. Theendoscopic light source of claim 10, wherein the intervening opticalcomponent includes a diffuser or a mixing rod.
 12. The endoscopic lightsource of claim 10, wherein the plurality of optical fibers includes aplurality of plastic optical fibers and wherein the intervening opticalcomponent includes a plurality of glass fibers.
 13. The endoscopic lightsource of claim 1, wherein the first emitter includes a first laseremitter and the second emitter includes a second laser emitter and thethird emitter includes a third laser emitter.
 14. The endoscopic lightsource of claim 13, wherein one of the first emitter, the secondemitter, and the third emitter emits a red light and wherein one of thefirst emitter, the second emitter, and the third emitter emits a greenlight, and wherein one of the first emitter, the second emitter, and thethird emitter emits a blue light.
 15. The endoscopic light source ofclaim 1, wherein the first angle is larger than the second angle withrespect to the waveguide comprising the plurality of optical fibers. 16.The endoscopic light source of claim 1, wherein the first angle ismeasured as an angle between light emitted by the first emitter and anaxis perpendicular to a collection region of the waveguide, and whereinthe second angle is measured as an angle between light emitted by thesecond emitter and the axis perpendicular to a collection region of thewaveguide.